Lithographic processes are used extensively in the manufacture and fabrication of semiconductor devices, integrated circuits, and microelectronic devices. As a result, new methods and materials are being developed for use in lithography processes everyday. At the same time, however, semiconductor devices, integrated circuits, and microelectronic devices are being miniaturized. This miniaturization strains the existing lithography technologies and requires the development of new technologies cable of producing smaller devices.
To date, extreme ultra-violet (EUV) lithography is one of the most promising next generation lithography technologies that may be used with devices having nanoscale or sub-250 nm features. SUV lithography may also be used to further push the limits of miniaturization. The goal of EUV lithography has been to create lithography capable of handling a sub-50 nm node. However, the use of EUV lithography has been limited by the absence or lack of materials that can be used in the EUV lithography processes. For instance, a lack of resist materials capable of withstanding currently used etching techniques is problematic.
In photolithography and EUV lithography feature size is ultimately limited by the wavelength of the exposing radiation. EUV radiation at a wavelength of 13.4 nm is believed to be the choice for next generation lithography processes because it should be able to produce features at the sub-50 nm level. Resist transparency is a key challenge for the technology. Absorption control is another challenge. At the narrow wavelengths of EUV lithography, absorption depends on the atomic composition of a material. However, many materials have high absorption levels and the current resist materials used in lithography processes are not suitable for EUV lithography processes. Furthermore, many of the resist materials used in lithography processes include large amounts of oxygen and fluorine, which are high absorbing elements that may not be suitable for use with EUV lithography processes and especially those processes involving sub-50 nm feature sizes.
Therefore, it is desirable to create new materials and processes that may be used with lithography and especially EUV lithography processes.